Gmplsmpls node and ip mpls node

ABSTRACT

A network is realized having GMPLS and IP/MPLS mixed, in which an IP/MPLS node can be operated as is without replacing the IP/MPLS node with a node having a GMPLS function, even if the GMPLS and IP/MPLS are mixed. To match with the protocol of the IP/MPLS node outside of a GMPLS cloud, the GMPLS+IP/MPLS node (edge) establishes a PSC-LSP between GMPLS+IP/MPLS nodes (edge), uses the PSC-LSP as an IP/MPLS link from the viewpoint of the IP/MPLS node, and operates signaling of an MPLS-LSP establishment requested from the IP/MPLS.

TECHNICAL FIELD

The present invention relates to a connection scheme between networksusing different switching schemes. In other words, the present inventionrelates to a connection scheme between networks managed by differentmethods. Particularly, the present invention relates to a network whereGMPLS (Generalized Multi-Protocol Label Switching) networks and IP/MPLS(Internet Protocol/Multi-Protocol Label Switching) networks are mixed.

Priority is claimed on Japanese Patent Application No. 2003-85423 filedMar. 26, 2003, Japanese Patent Application No. 2003-296440 filed Aug.20, 2003, and Japanese Patent Application No. 2004-56129 filed Mar. 1,2004, the contents of which are incorporated herein by reference.

BACKGROUND ART

Hereunder is a list of documents referred to in the present description.

Non Patent Document 1: E. Rosen, A. Viswanathan, and R. Callon,“Multiprotocol Label Switching Architecture”, RFC 3031.

Non Patent Document 2: J. Moy, “OSPF Version 2”, RFC 2328.

Non Patent Document 3: R. Coltun, “The OSPF Opaque LSA Option”, RFC2370.

Non Patent Document 4: K. Kompella and Y. Rekhter, “OSPF Extension inSupport of Generalized MPLS”, IETF draft,draft-ietf-ccamp-ospf-gmpls-extensions-09.txt, December 2002.

Non Patent Document 5: P. Ashwood-Smith et al, “Generalized MPLSSignaling-RSVP-TE Extensions”, IETF draft,draft-ietf-mpls-generalized-rsvp-te-09.txt, August 2002.

Non Patent Document 6: D. Awduche et al., “RSVP-TE: Extensions to RSVPfor LSP Tunnels”, RFC 3209, December 2001.

Non Patent Document 7: A. Banerjee et al, “Generalized MultiprotocolLabel Switching: An Overview of Routing and Management Enhancements”,IEEE Commun. Mag., pp. 144-150, January 2001.

Non Patent Document 8: D. katz et al., “Traffic Engineering Extensionsto OSPF Version 2”, IETF draft, draft-katz-yeung-ospf-traffic-10.txt,June 2003.

A conventional network comprising IP/MPLS nodes is shown in FIG. 21. Inthe network within the IP/MPLS, the switching capability of the nodeinterface is all PSC (Packet Switching Capable). MPLS architecture isdefined in order to support data transfer based on labels (for example,refer to Non Patent Document 1). In RFC3031, an LSR (Label SwitchingRouter) means a node which has a data transfer plane which can identifythe border of an IP packet or a cell (labeled IP packet), and whichperforms data transfer processing according to the contents of the IPpacket header or cell header. In GMPLS, the LSR is not only the nodethat performs data transfer processing according to the contents of theIP packet header or cell header. The LSR in GMPLS includes a devicewhich performs transfer processing based on the information of a timeslot, a wavelength, or a physical port of a file.

On the other hand, the LSR interface in GMPLS is classified into four byswitching capability, namely: PSC (Packet Switch Capable), TDM(Time-Division Multiplex Capable), LSC (Lambda Switch Capable) and FSC(Fiber Switch Capable). Moreover, the concept of labels in GMPLS isshown in FIG. 22A to FIG. 22D.

(Description of PSC)

A PSC interface can identify the border of an IP packet or a cell, andperforms data transfer processing according to the contents of the IPpacket header or cell header. In FIG. 22A, in the packet layer, a labeluniquely defined by each link is defined, and the label is given to theIP packet to form an LSP (Label Switch Path). The link in FIG. 22A is alink which is defined between LSRs in order to transfer the IP packet.If transferring the IP packet on SDH/SONET, it becomes a SDH/SONET path.If transferring on Ethernet (registered trademark), it becomes anEthernet (registered trademark).

(Description of TDM)

The TDM interface performs data transfer processing based on aperiodically repeated time slot. In FIG. 22, in the TDM layer, the labelbecomes the time slot. An example of a TDM interface is a DXC (datacross-connect) interface, which connects the time slot allocated on theinput side and the time slot allocated on the output side, to form a TDMpath, that is a SDH/SONET path. The link may be a wavelength path insome cases, or may simply be a fiber in other cases.

(Description of LSC)

An LSC interface performs data transmission processing based on thewavelength in the fiber used for transferring the data. In FIG. 22C, inthe Lambda layer, the label becomes the wavelength. An example of an LSCinterface is an OXC (optical cross-connect) interface, which connectsthe wavelength allocated on the input side and the wavelength allocatedon the output side to form a Lambda path. An OXC interface having LSCperforms switching in wavelength units.

(Description of FSC)

An FSC interface performs data transmission processing based on theposition of an actual physical port of a fiber used for transferring thedata. In FIG. 22D, in the fiber layer, the label becomes the fiber. Anexample of an FSC interface is an OXC interface, which connects theinput side fiber and the output side fiber to form a fiber path. The OXCinterface having FSC performs switching in fiber units. The link meansthe physical aggregate of fibers, including conduits, etc.

The above interfaces of switching capability can be hierarchized foruse. For example, FSC, LSC, TDM and PSC in sequential order from theupper hierarchy. In GMPLS, the path with respect to the respectiveswitching capability mentioned above is also called LSP. FIG. 23 showsthe hierarchical structure of LSP. PSC-LSP belongs to TDM-LSP, and thePSC-LSP link becomes TDM-LSP. TDM-LSP belongs to LSC-LSP, and theTDM-LSP link becomes LSC-LSP. LSC-LSP becomes FSC-LSP and the LSC-LSPlink becomes FSC-LSP. Moreover, considering a case where the TDM layeris omitted, PSC-LSP belongs to LSC-LSP, and the PSC-LSP link becomesLSC-LSP. The relation of LSC-LSP and FSC-LSP is similar to that of FIG.22B. As the layer becomes lower, the LSP band becomes broader.

In such conventional techniques, for example as shown in FIG. 24, ifGMPLS nodes 2, 3, 4, 5, and 6 being GMPLS nodes having PSC switchingcapability and LSC switching capability, and IP/MPLS nodes 1 and 7having only the PSC function are mixed, the IP/MPLS nodes are notmatched with GMPLS protocol. Therefore, as shown in FIG. 25 in theconventional technique, all nodes have to be replaced by GMPLS nodeswhich are operated by GMPLS protocol in order to match the IP/MPLS nodeshaving only PSC function with GMPLS protocol. Accordingly, theinstallation cost becomes higher for installing the GMPLS nodes.

In GMPLS, there are routing protocols and signaling protocols for GMPLSwith the extended IP/MPLS. In the routing protocol for GMPLS, GMPLSregards LSPs in all hierarchies as the link from the viewpoint of theupper layer, and advertise the link state. Accordingly, the nodes in theGMPLS network hold all link states, and have the topologies of therespective layers. A database of the topologies is made for trafficengineering, and is called a GMPLS-TED (Traffic Engineering Database).The respective nodes hold the GMPLS-TED.

In the signaling protocol, there are signaling protocols for GMPLS, andall GMPLS nodes are required to operate the signaling protocol forGMPLS. FIGS. 26A and 26B show how LSC-LSPs are established on thehierarchy of PSC-LSP. The LSC-LSP is established between node 2 and node4. The LSC-LSP is established between node 4 and node 5. The PSC-LSP isestablished through the two LSC-LSPs between node 21 and node 27.

FIG. 27 shows the structure of a conventional GMPLS node. As shown inFIG. 27, the conventional GMPLS node comprises; a GMPLS signaling unit10 which controls the signaling of GMPLS, a GMPLS routing unit 11 whichcontrols the routing of GMPLS, a GMPLS-TED unit 14 which stores the linkstate information of the GMPLS network, a control unit controller 20which controls the respective units, and a switch unit 19 which performspacket switching.

DISCLOSURE OF INVENTION

The present invention is based on such background, with an object ofproviding a network having GMPLS and IP/MPLS mixed, in which an IP/MPLSnode can be operated as is without replacing the IP/MPLS node with theGMPLS node, even if the GMPLS node and IP/MPLS node are mixed.

In the present invention, it is not necessary to replace all nodes withGMPLS. The node which was originally the IP/MPLS node can be used as theIP/MPLS as is.

A GMPLS cloud which is composed of only nodes having GMPLS functions isconstructed. A node in the GMPLS cloud which is connected to the IP/MPLSnode by a physical link is called an edge node. As this edge node, thereis arranged a GMPLS+IP/MPLS node which can process the GMPLS protocoland the IP/MPLS protocol (hereunder, GMPLS+IP/MPLS node (edge)).Moreover, a node except for the GMPLS+IP/MPLS node (edge) being the nodehaving the GMPLS function in the GMPLS cloud is called a core node. Asthe core node, there is arranged either one of the GMPLS+IP/MPLS node orthe GMPLS node. The GMPLS+IP/MPLS node as the core node is denoted byGMPLS+IP/MPLS node (core). The GMPLS node as the core node is denoted byGMPLS node (core).

The GMPLS+IP/MPLS node (edge) supports the following functions so as tomatch with the protocol of the IP/MPLS node outside of the GMPLS cloud.The PSC-LSP is established between the GMPLS+IP/MPLS nodes (edge). ThePSC-LSP is used as the IP/MPLS link from the aspect of IP/MPLS node. Thesignaling of MPLS-LSP establishment requested from the IP/MPLS isoperated. The GMPLS+IP/MPLS node (edge) has the GMPLS-TED and theIP/MPLS-TED. The IP/MPLS node has the IP/MPLS-TED. The GMPLS+IP/MPLSnode (core) or the GMPLS node (core) has the GMPLS-TED.

Accordingly, the IP/MPLS node can be operated in a network having GMPLSmixed, in a similar way to that of a network having IP/MPLS only,without operating the GMPLS protocol.

That is, a first aspect of the present invention is a GMPLS+IP/MPLS nodewhich is used in a network in which a GMPLS network and an IP networkare mixed, the GMPLS network comprising a node having a GMPLS function,the IP network comprising an IP/MPLS (Internet Protocol/Multi ProtocolLabel Switching) node, and which constitutes the GMPLS network, andwhich processes a GMPLS protocol and an IP/MPLS protocol, theGMPLS+IP/MPLS node.

Here, the present invention comprises: a device which establishes aGMPLS label path of a packet layer with another GMPLS+IP/MPLS node inthe GMPLS network; and a device which tunnel transfers a packettransferred from the IP/MPLS node with the other GMPLS+IP/MPLS nodethrough the GMPLS label path.

Therefore, viewing from the IP/MPLS node, the GMPLS label path of thepacket layer established in the GMPLS network looks like a label path inthe IP/MPLS network. Accordingly, a network having the IP/MPLS and theGMPLS mixed can be configured.

There may be provided a device which advertises link state informationof the GMPLS label path of the packet layer to the IP/MPLS node by arouter LSA (Label Switching Advertisement) as a normal link in theIP/MPLS node.

Therefore, the link state information of the GMPLS label path of thepacket layer in the GMPLS network can be advertised in a form acceptableby the IP/MPLS node.

There may be provided: a device which holds the link state informationhaving the GMPLS label path of the packet layer advertised as the link;and a device which holds link state information inside of the GMPLSnetwork.

Therefore, the link state information of both the GMPLS network and theIP/MPLS network can be held to deal with both networks.

There may be provided a device which converts a link of PSC-LSP (PacketSwitch Capable-Label Switch Path) used for IP/MPLS from an unnumberedsystem into a numbered system to advertise as the link of the numberedsystem. Alternatively, there may be provided a device which advertisesthe GMPLS label switch path of the packet layer as a link of a numberedsystem.

Therefore, the link state information of the GMPLS label path of thepacket layer in the GMPLS network can be advertised in a form acceptableby the IP/MPLS node.

There may be provided: a device which performs processing inside of theGMPLS network in accordance with an unnumbered system; and a devicewhich converts a link of PSC-LSP used for IP/MPLS from the unnumberedsystem into a numbered system to advertise as the link of the numberedsystem. Alternatively, there may be provided: a device which performsprocessing inside of the GMPLS network in accordance with an unnumberedsystem; and a device which converts the GMPLS label switch path of thepacket layer from the unnumbered system into a numbered system toadvertise as the link of the numbered system.

Therefore, convenient processes may be respectively performed in theGMPLS network and the IP/MPLS network.

In such a numbered system, there may be provided: a device whichpreviously stores an IP address; and a device which uses the stored IPaddress as an IP address of the link of the numbered system.

There may be provided an LSA converting device which converts an OpaqueLSA expressing a D-plane label path in the GMPLS network into a routerLSA, wherein when the label path is a point-to-point Link type of anumbered system, the LSA converting device may change a Link-StateAdvertisement Type to 1 corresponding to the router LSA, copy anAdvertising Router value and an LS Sequence number value, copy a Link IDfield value in the Opaque LSA to a Link ID field of the router LSA, andcopy a Local interface IP address field value in the Opaque LSA to aLink Data field of the router LSA expressing a router interface's IPaddress.

Therefore, it becomes possible to generate a router LSA which plays arole of advertising the GMPLS label path to the MPLS network.

There may be provided an LSA converting device which converts an OpaqueLSA expressing a D-plane label path in the GMPLS network into a routerLSA, wherein when the label path is a point-to-point Link type of anunnumbered system, the LSA converting device may change a Link-StateAdvertisement Type to 1 corresponding to the router LSA, copy anAdvertising Router value and an LS Sequence number value, copy a Link IDfield value in the Opaque LSA to a Link ID field of the router LSA, andcopy a Link Local Identifiers field value in the Opaque LSA to a LinkData field of the router LSA expressing an ifIndex value.

Therefore, it becomes possible to generate a router LSA which plays arole of advertising the GMPLS label path to the MPLS network.

There may be provided an LSA converting device which converts an OpaqueLSA expressing a D-plane label path in the GMPLS network into a routerLSA, wherein when the label path is a multi-access Link type, the LSAconverting device may change a Link-State Advertisement Type to 1corresponding to the router LSA, copy an Advertising Router value and anLS Sequence number value, copy a Link ID field value in the Opaque LSAto a Link ID field of the router LSA, and copy a Local interface IPaddress field value in the Opaque LSA to a Link Data field of the routerLSA expressing a router interface's IP address.

Therefore, it becomes possible to generate a router LSA which plays arole of advertising the GMPLS label path to the MPLS network.

There may be provided: an LSA identifying device which receives a routerLSA generated by another GMPLS+IP/MPLS node and identifies whether therouter LSA advertises a C-plane of the GMPLS network, or whether therouter LSA is obtained by converting an Opaque LSA expressing the GMPLSlabel path; and a link state holding device which holds link stateinformation of the GMPLS network, wherein the LSA identifying device maysearch the link state holding device of the GMPLS+IP/MPLS node itselfusing an Advertising Router value and an LS Sequence number valueincluded in the received router LSA as a key, and when link stateinformation having the same Advertising Router and LS Sequence number asthe received router LSA is held in the link state holding device, theLSA identifying device may judge that the received router LSA isobtained by converting the Opaque LSA expressing the GMPLS label path.

Therefore, it becomes possible to identify whether the router LSAadvertised to the network expresses the C-plane of the GMPLS network, orwhether the router LSA is generated by converting the Opaque LSAexpressing the D-plane label path. Consequently, the GMPLS node canjudge which router LSA should be used for generating the C-planetopology and which router LSA should be used for generating the D-planetopology.

There may be provided an LSA converting device which converts an OpaqueLSA expressing a D-plane label path in the GMPLS network into a routerLSA, wherein when the label path is a point-to-point Link type of anumbered system, the LSA converting device may change a Link-StateAdvertisement Type to 1 corresponding to the router LSA, copy anAdvertising Router value, turn on a label path conversion flag whichshows that the Opaque LSA expressing the D-plane label path in the GMPLSnetwork is converted into the router LSA, copy a Link ID field value inthe Opaque LSA to a Link ID field of the router LSA, and copy a Localinterface IP address field value in the Opaque LSA to a Link Data fieldof the router LSA expressing a router interface's IP address.

Therefore, it becomes possible to generate a router LSA which plays arole of advertising the GMPLS label path to the MPLS network.

There may be provided an LSA converting device which converts an OpaqueLSA expressing a D-plane label path in the GMPLS network into a routerLSA, wherein when the label path is a point-to-point Link type of anunnumbered system, the LSA converting device may change a Link-StateAdvertisement Type to 1 corresponding to the router LSA, copy anAdvertising Router value, turns on a label path conversion flag whichshows that the Opaque LSA expressing the D-plane label path in the GMPLSnetwork is converted into the router LSA, copy a Link ID field value inthe Opaque LSA to a Link ID field of the router LSA, and copy a LinkLocal Identifiers field value in the Opaque LSA to a Link Data field ofthe router LSA expressing an ifIndex value.

Therefore, it becomes possible to generate a router LSA which plays arole of advertising the GMPLS label path to the MPLS network.

There may be provided an LSA converting device which converts an OpaqueLSA expressing a D-plane label path in the GMPLS network into a routerLSA, wherein when the label path is a multi-access Link type, the LSAconverting device may change a Link-State Advertisement Type to 1corresponding to the router LSA, copy an Advertising Router value, turnon a label path conversion flag which shows that the Opaque LSAexpressing the D-plane label path in the GMPLS network is converted intothe router LSA, copy a Link ID field value in the Opaque LSA to a LinkID field of the router LSA, and copy a Local interface IP address fieldvalue in the Opaque LSA to a Link Data field of the router LSAexpressing a router interface's IP address.

Therefore, it becomes possible to generate a router LSA which plays arole of advertising the GMPLS label path to the MPLS network.

There may be provided an LSA identifying device which receives a routerLSA generated by another GMPLS+IP/MPLS node and identifies whether therouter LSA advertises a C-plane of the GMPLS network, or whether therouter LSA is obtained by converting an Opaque LSA expressing the GMPLSlabel path; and a link state holding device which holds link stateinformation of the GMPLS network, wherein the LSA identifying device maysearch the link state holding device of the GMPLS+IP/MPLS node itselfusing an Advertising Router value and a label path conversion flagincluded in the received router LSA as a key, and when link stateinformation having the same Advertising Router value as the receivedrouter LSA and having the label path conversion flag turned on is heldin the link state holding device, the LSA identifying device may judgethat the received router LSA is obtained by converting the Opaque LSAexpressing the GMPLS label path.

Therefore, it becomes possible to identify whether the router LSAadvertised to the network expresses the C-plane of the GMPLS network, orwhether the router LSA is generated by converting the Opaque LSAexpressing the D-plane label path. Consequently, the GMPLS node canjudge which router LSA should be used for generating the C-planetopology and which router LSA should be used for generating the D-planetopology.

There may be provided a device which, when a C-plane topology of theGMPLS network is advertised by the router LSA, an IP/MPLS node receivingthe router LSA recognizes the C-plane topology of the GMPLS network, andan IP/MPLS node having information regarding the topology outputs arequest to specify the C-plane of the GMPLS network and to establish anMPLS label path, and if there is a GMPLS label path having thecorresponding nodes on opposite ends of a C-plane link on a routespecified by the request, allocates the specified route to the GMPLSlabel path.

There may be provided a device which, when a C-plane topology of theGMPLS network is advertised by the router LSA, an IP/MPLS node receivingthe router LSA recognizes the C-plane topology of the GMPLS network, andan IP/MPLS node having information regarding the topology outputs arequest to specify the C-plane of the GMPLS network and to establish anMPLS label path, and if there is no GMPLS label path having thecorresponding nodes on opposite ends of a C-plane link on a routespecified by the request, in response to an MPLS label pathestablishment request output from the IP/MPLS node, newly establishes alabel path on a D-plane corresponding to opposite nodes of the C-planelink, and allocates the specified route to the newly established labelpath.

Therefore, in the case where the MPLS node specifies the C-plane of theGMPLS network as the route, even if there is no corresponding label pathon the corresponding link, it becomes possible to automatically andnewly establish the corresponding label path and establish the MPLS pathusing the new label path.

There may be provided a device which, when the GMPLS label path havingthe corresponding nodes on opposite ends of the C-plane link of theGMPLS network specified by the IP/MPLS node is allocated, and if theGMPLS+IP/MPLS node itself directly receives the request from the IP/MPLSnode, transfers data which is transferred from the IP/MPLS node, not tothe route specified by the IP/MPLS node, but to the allocated GMPLSlabel path.

By installing the abovementioned invention related to the routingprotocol, in the GMPLS node, it becomes possible to interconnect theGMPLS network and the IP/MPLS network.

A second aspect of the present invention is an IP/MPLS node which isused in a network in which a GMPLS network and an IP network are mixed,the GMPLS network comprising a node having a GMPLS function, the IPnetwork comprising an IP/MPLS node, and which is connected to the GMPLSnetwork.

Here, in the present invention, a GMPLS+IP/MPLS node which constitutesthe GMPLS network and which is capable of processing a GMPLS protocoland an IP/MPLS protocol establishes a GMPLS label path of a packet layerwith another GMPLS+IP/MPLS nodes in the GMPLS network, the IP/MPLS nodecomprising a device which holds link state information having a GMPLSlabel path of the packet layer advertised as a link.

A third aspect of the present invention is a network comprising aGMPLS+IP/MPLS node and an IP/MPLS node according to the presentinvention wherein the GMPLS and the IP/MPLS are mixed.

A fourth aspect of the present invention is a packet communicationmethod in a network in which a GMPLS network and an IP network aremixed, the GMPLS network comprising a node having a GMPLS function, theIP network comprising an IP/MPLS node, and the IP/MPLS node transfers apacket with the node having the GMPLS function.

Here, the present invention comprises: a step of providing aGMPLS+IP/MPLS node which is capable of processing a GMPLS protocol andan IP/MPLS protocol and which is directly connected to the IP networkamong nodes having the GMPLS function constituting the GMPLS network; astep of establishing a GMPLS label path of a packet layer with anotherGMPLS+IP/MPLS node in the GMPLS network by the GMPLS+IP/MPLS node; and astep of tunnel transferring a packet transferred from the IP/MPLS nodewith the other GMPLS+IP/MPLS node through the GMPLS label path.

Link state information of the GMPLS label path of the packet layer maybe advertised to the IP/MPLS node by a router LSA as a normal link inthe IP/MPLS node.

Link state information of the GMPLS label path of the packet layer maybe advertised to the IP/MPLS node by an Opaque LSA which can beprocessed by an MPLS router as a normal link in the IP/MPLS node.

Link state information having the GMPLS label path of the packet layeradvertised as the link may be held, and link state information inside ofthe GMPLS network may be held.

A link of PSC-LSP used for IP/MPLS may be converted from an unnumberedsystem into a numbered system and be advertised as the link of thenumbered system.

The GMPLS network may perform processing in accordance with anunnumbered system, and a link of PSC-LSP used for IP/MPLS may beconverted from the unnumbered system into a numbered system and beadvertised as the link of the numbered system.

The GMPLS label switch path of the packet layer may be advertised as thelink of a numbered system.

The GMPLS network may perform processing in accordance with anunnumbered system, and the GMPLS label switch path of the packet layermay be converted from the unnumbered system into a numbered system, andbe advertised as the link of the numbered system.

An IP address may be previously stored, and the stored IP address may beused as an IP address of the link of the numbered system.

In order to convert an Opaque LSA expressing a D-plane label path in theGMPLS network into a router LSA, when the label path is a point-to-pointLink type of a numbered system, a Link-State Advertisement Type may bechanged to 1 corresponding to the router LSA, an Advertising Routervalue and an LS Sequence number value may be copied, a Link ID fieldvalue in the Opaque LSA may be copied to a Link ID field of the routerLSA, and a Local interface IP address field value in the Opaque LSA maybe copied to a Link Data field of the router LSA expressing a routerinterface's IP address.

In order to convert an Opaque LSA expressing a D-plane label path in theGMPLS network into a router LSA, when the label path is a point-to-pointLink type of an unnumbered system, a Link-State Advertisement Type maybe changed to 1 corresponding to the router LSA, an Advertising Routervalue and an LS Sequence number value may be copied, a Link ID fieldvalue in the Opaque LSA may be copied to a Link ID field of the routerLSA, and a Link Local Identifiers field value in the Opaque LSA may becopied to a Link Data field of the router LSA expressing an ifIndexvalue.

In order to convert an Opaque LSA expressing a D-plane label path in theGMPLS network into a router LSA, when the label path is a multi-accessLink type, a Link-State Advertisement Type may be changed to 1corresponding to the router LSA, an Advertising Router value and an LSSequence number value may be copied, a Link ID field value in the OpaqueLSA may be copied to a Link ID field of the router LSA, and a Localinterface IP address field value in the Opaque LSA may be copied to aLink Data field of the router LSA expressing a router interface's IPaddress.

A router LSA generated by another GMPLS+IP/MPLS node may be received,and in order to identify whether the router LSA advertises a C-plane ofthe GMPLS network or whether the router LSA is obtained by converting anOpaque LSA expressing the GMPLS label path, a link state holding deviceof its own GMPLS+IP/MPLS node which holds link state information of theGMPLS network may be searched, using an Advertising Router value and anLS Sequence number value included in the received router LSA as a key,and when link state information having the same Advertising Router andLS Sequence number as the received router LSA is held in the link stateholding device, it may be judged that the received router LSA isobtained by converting the Opaque LSA expressing the GMPLS label path.

In order to convert an Opaque LSA expressing a D-plane label path in theGMPLS network into a router LSA, when the label path is a point-to-pointLink type of a numbered system, a Link-State Advertisement Type may bechanged to 1 corresponding to the router LSA, an Advertising Routervalue may be copied, a label path conversion flag which shows that theOpaque LSA expressing the D-plane label path in the GMPLS network may beconverted into the router LSA may be turned on, a Link ID field value inthe Opaque LSA may be copied to a Link ID field of the router LSA, and aLocal interface IP address field value in the Opaque LSA may be copiedto a Link Data field of the router LSA expressing a router interface'sIP address.

In order to convert an Opaque LSA expressing a D-plane label path in theGMPLS network into a router LSA, when the label path is a point-to-pointLink type of an unnumbered system, a Link-State Advertisement Type maybe changed to 1 corresponding to the router LSA, an Advertising Routervalue may be copied, a label path conversion flag which shows that theOpaque LSA expressing the D-plane label path in the GMPLS network may beconverted into the router LSA is turned on, a Link ID field value in theOpaque LSA may be copied to a Link ID field of the router LSA, and aLink Local Identifiers field value in the Opaque LSA may be copied to aLink Data field of the router LSA expressing an ifIndex value.

In order to convert an Opaque LSA expressing a D-plane label path in theGMPLS network into a router LSA, when the label path is a multi-accessLink type, a Link-State Advertisement Type may be changed to 1corresponding to the router LSA, an Advertising Router value may becopied, a label path conversion flag which shows that the Opaque LSAexpressing the D-plane label path in the GMPLS network is converted intothe router LSA may be turned on, a Link ID field value in the Opaque LSAmay be copied to a Link ID field of the router LSA, and a Localinterface IP address field value in the Opaque LSA may be copied to aLink Data field of the router LSA expressing a router interface's IPaddress.

A router LSA generated by another GMPLS+IP/MPLS node may be received,and in order to identify whether the router LSA advertises a C-plane ofthe GMPLS network or whether the router is obtained by converting anOpaque LSA expressing the GMPLS label path, a link state holding deviceof its own GMPLS+IP/MPLS node which holds link state information of theGMPLS network may be searched using an Advertising Router value and alabel path conversion flag included in the received router LSA as a key,and when link state information having the same Advertising Router valueas the received router LSA and having the label path conversion flagturned on is held in the link state holding device, it may be judgedthat the received router LSA is obtained by converting the Opaque LSAexpressing the GMPLS label path.

The GMPLS+IP/MPLS node may advertise a C-plane topology of the GMPLSnetwork by the router LSA, an IP/MPLS node receiving the router LSA mayrecognize the C-plane topology of the GMPLS network, an IP/MPLS nodehaving information regarding the topology may output a request tospecify the C-plane of the GMPLS network and to establish an MPLS labelpath, and if there is a GMPLS label path having the corresponding nodeson opposite ends of a C-plane link on a route specified by the request,the GMPLS+IP/MPLS node may allocate the specified route to the GMPLSlabel path.

The GMPLS+IP/MPLS node may advertise a C-plane topology of the GMPLSnetwork by the router LSA, an IP/MPLS node receiving the router LSA mayrecognize the C-plane topology of the GMPLS network, an IP/MPLS nodehaving information regarding the topology may output a request tospecify the C-plane of the GMPLS network and to establish an MPLS labelpath, and if there is no GMPLS label path having the corresponding nodeson opposite ends of a C-plane link on a route specified by the request,in response to an MPLS label path establishment request output from theIP/MPLS node as a trigger, the GMPLS+IP/MPLS node may newly establish alabel path on a D-plane corresponding to opposed nodes of the C-planelink, and may allocate the specified route to the newly establishedlabel path.

When the GMPLS label path having the corresponding nodes on oppositeends of the C-plane link of the GMPLS network specified by the IP/MPLSnode is allocated, a GMPLS+IP/MPLS node which directly receives therequest from the IP/MPLS node may transfer data which is transferredfrom the IP/MPLS node, not to the route specified by the IP/MPLS node,but to the allocated GMPLS label path.

The IP/MPLS node may hold link state information having the GMPLS labelpath of the packet layer advertised as a link.

A fifth aspect of the present invention is a method for configuring anetwork in which GMPLS and IP/MPLS are mixed, the method comprises thesteps of: providing a GMPLS+IP/MPLS node which transfers a packet usingthe packet communication method of the present invention; and providingan IP/MPLS node which transfers the packet using the packetcommunication method of the present invention.

According to the present invention, it becomes possible to realize anetwork having GMPLS and IP/MPLS mixed, in which the IP/MPLS node can beoperated as is without replacing the IP/MPLS node with a node having aGMPLS function, even if the GMPLS and IP/MPLS are mixed.

Moreover, according to the present invention, in the case where theGMPLS network and the IP/MPLS network are connected, the routingprotocol is normally operated. By performing traffic engineering basedon this, it becomes possible to distribute the traffic, and toeffectively use the network resources.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A to FIG. 1C is a conceptual diagram of tunnel transfer in anembodiment of the present invention.

FIG. 2 is a flowchart showing a packet communication protocol of theembodiment of the present invention.

FIG. 3 shows a network comprising IP/MPLS nodes and GMPLS nodes of theembodiment of the present invention.

FIG. 4 is a block diagram of a control unit of a GMPLS edge node of theembodiment of the present invention.

FIG. 5 is a block diagram of a control unit of a GMPLS core node of theembodiment of the present invention.

FIG. 6 is a block diagram of a control unit of an IP/MPLS node of theembodiment of the present invention.

FIG. 7A shows a numbered system in a GMPLS cloud, and FIG. 7B shows anumbered system outside of a GMPLS cloud.

FIG. 8A shows a numbered system in a GMPLS cloud, and FIG. 8B shows anumbered system outside of a GMPLS cloud.

FIG. 9 is an explanatory diagram of the allocation of IP addresses to anumbered link of the embodiment of the present invention.

FIG. 10 is a block diagram of a control unit of a GMPLS edge node of theembodiment of the present invention.

FIG. 11 is a block diagram of a control unit of a GMPLS edge node of theembodiment of the present invention.

FIG. 12 shows a network comprising IP/MPLS nodes, GMPLS+IP/MPLS nodesand GMPLS nodes.

FIG. 13A to FIG. 13C is an explanatory diagram of an establishmentcondition of LSP establishment in an example 4.

FIG. 14 shows a management condition of link state information in anetwork comprising IP/MPLS nodes, GMPLS+IP/MPLS nodes and GMPLS nodes.

FIG. 15 is a block diagram showing the structure of an LSA convertingunit provided for the GMPLS+IP/MPLS node according to an example 6.

FIG. 16 is a table showing the correspondence of parameters of an OpaqueLSA and a router LSA.

FIG. 17 is a block diagram showing a structure of a router LSAidentification unit provided for the GMPLS+IP/MPLS node according to anexample 7.

FIG. 18 is a block diagram showing a structure of a network forexplaining an example 10.

FIG. 19 shows a path establishment sequence of the network of example 10comprising GMPLS+IP/MPLS nodes.

FIG. 20 shows a path establishment sequence of the network of an example11 comprising GMPLS+IP/MPLS nodes.

FIG. 21 shows a network comprising IP/MPLS nodes.

FIG. 22A to FIG. 22D shows the concept of labels.

FIG. 23 is an explanatory diagram of LSP hierarchization.

FIG. 24 is an explanatory diagram of the case where GMPLS nodes areinserted in a network comprising IP/MPLS nodes.

FIG. 25 shows a conventional network comprising GMPLS nodes.

FIG. 26A and FIG. 26B shows LSP hierarchization in the conventionalnetwork comprising GMPLS nodes.

FIG. 27 is a block diagram of a control unit for the conventional GMPLSnode.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereunder is a description of GMPLS+IP/MPLS nodes, GMPLS nodes, IP/MPLSnodes, networks, and a method for configuring a network, of anembodiment of the present invention, with reference to the drawings.

In the network of the embodiment of the present invention, as shown inFIG. 1A to FIG. 1C, an IP packet transferred from an IP/MPLS node istransferred in accordance with tunnel transfer using an MPLS-LSP (FIG.1A) or a PSC-LSP (FIG. 1B), that is a GMPLS label path of a packet layerestablished between a GMPLS+IP/MPLS node (edge) 2 and a GMPLS+IP/MPLSnode (edge) 5. In the embodiment of the present invention, thedescription is only regarding one-way, to make the description easilyunderstood. However, the transferring direction may be either two-way orone-way. The description of two-way is omitted since it can be easilydeduced from the description of one-way.

A packet communication protocol in the network of the embodiment of thepresent invention is described with reference to FIG. 2. TheGMPLS+IP/MPLS node detects the link to be connected to the GMPLS+IP/MPLSitself (Step 1). The link with an IP/MPLS node is established (Step 2).Then, the GMPLS+IP/MPLS node recognize itself as the GMPLS+IP/MPLS node(edge) and sets the mode (Step 3). Subsequently, the GMPLS label path ofthe packet layer is established with another GMPLS+IP/MPLS node (edge)in the GMPLS network (Step 4). When the establishment of the GMPLS labelpath of the packet layer is completed, the packet transferred from theIP/MPLS node is tunnel transferred to the other GMPLS+IP/MPLS nodes(edge) (Step 5).

As shown in FIG. 3, the GMPLS+IP/MPLS nodes of the embodiment of thepresent invention are used in the network in which a GMPLS network andan IP network are mixed and the GMPLS network comprises nodes having theGMPLS function and the IP network comprises IP/MPLS nodes, and theGMPLS+IP/MPLS nodes constitute the GMPLS network and can deal with theGMPLS protocol and the IP/MPLS protocol.

Here, as shown in FIG. 4, a feature of the embodiment of the presentinvention is that there is provided a GMPLS signaling unit 10 whichestablishes the GMPLS label path of the packet layer with anotherGMPLS+IP/MPLS node in the GMPLS network, and a GMPLS routing unit 11which tunnel transfers the packet transferred from the IP/MPLS node withthe other GMPLS+IP/MPLS node through the GMPLS label path.

Furthermore, there is provided an IP/MPLS-TED unit 13 which takes theGMPLS label path of the packet layer as a normal link in the IP/MPLSnode and advertises the link state information to the IP/MPLS node by arouter LSA. The IP/MPLS-TED unit 13 holds the link state informationadvertised by using the GMPLS label path of the packet layer as thelink. Furthermore, it comprises a GMPLS-TED unit 14 which holds the linkstate information inside of the GMPLS network.

Moreover, as shown in FIG. 10, with respect to the PSC-LSP link used forIP/MPLS, there is provided an IP address pool 16 which converts anunnumbered system into a numbered system to advertise as the link of thenumbered system. Alternatively, as shown in FIG. 11, the GMPLS networkprocesses in accordance with the unnumbered system, and, there isprovided an IP address pool 16 and a numbered/unnumbered converting unit15 which converts the unnumbered system into the numbered system toadvertise as the link of the numbered system with respect to the PSC-LSPlink used for IP/MPLS. The numbered/unnumbered converting unit 15 canadvertise the GMPLS label switch path of the packet layer as the link ofthe numbered system.

Alternatively, it is also acceptable that the GMPLS network processes inaccordance with the unnumbered system, and the numbered/unnumberedconverting unit 15 and the IP address pool 16 are used to convert theGMPLS label switch path of the packet layer of the unnumbered systeminto a numbered system and advertise as the link of the numbered system.

The IP address pool 16 previously stores the IP address, and the storedIP address is used as the IP address of the link of the numbered system.

Moreover, the GMPLS+IP/MPLS node also includes an MPLS signaling unit 17and an IP/MPLS routing unit 18 as the function of the IP/MPLS node.

As shown in FIG. 6, the IP/MPLS node of the embodiment of the presentinvention comprises the IP/MPLS-TED unit 13 which holds the link stateinformation advertised using the GMPLS label path of the packet layer asthe link. A switch unit 19 switches the paths which are established tothe respective nodes.

The network of the embodiment of the present invention includes theGMPLS+IP/MPLS node and the IP/MPLS node of the embodiment of the presentinvention, wherein GMPLS and IP/MPLS are mixed.

Hereunder is a detailed description of the embodiment of the presentinvention.

EXAMPLE 1

The establishment condition of the LSP establishment in example 1 isdescribed using FIG. 1A to FIG. 1C. The GMPLS+IP/MPLS node (edge) 2 andthe GMPLS+IP/MPLS node (edge) 5 establish the PSC-LSP. Since the PSC-LSPis established through the LSC-LSP, the LSC-LSP is established beforethe PSC-LSP is established. The GMPLS+IP/MPLS node (edge) is used as anormal link of IP/MPLS with respect to the IP/MPLS node outside of theGMPLS cloud.

As shown in FIG. 1A, if an MPLS-LSP is established to an IP/MPLS node 1and an IP/MPLS node 7, the MPLS-LSP uses the PSC-LSP as a normal linkwith respect to the IP/MPLS node. The IP packet passes inside theMPLS-LSP.

Moreover, as shown in FIG. 1B, in some cases the IP/MPLS node 1transfers the IP packet to the IP/MPLS node 7 and not through theMPLS-LSP. In this case, the PSC-LSP established to the GMPLS+IP/MPLSnode (edge) 2 and the GMPLS+IP/MPLS node (edge) 5 is used as a normallink for the IP/MPLS node.

FIG. 3 shows the management condition of the link state information inthe network comprising the IP/MPLS node, the GMPLS+IP/MPLS node, and theGMPLS node. The GMPLS+IP/MPLS node or the GMPLS node in the GMPLS cloudmanages the link state information of the GMPLS. For example, if thelink state information is advertised in the GMPLS using the routingprotocol for the GMPLS, an Opaque LSA is used (for example, refer to NonPatent Documents 2, 3, and 4). Advertisement is performed in the sameform as that of the link between the IP/MPLS nodes, so that the PSC-LSPestablished between the GMPLS+IP/MPLS nodes (edge) is treated as anormal link for the IP/MPLS router. For example, if OSPF (Open ShortestPath First) routing protocol is used, the router LSA is used (forexample, refer to Non Patent Document 2).

As shown in FIG. 4, FIG. 10, and FIG. 11, the GMPLS+IP/MPLS node (edge)has the GMPLS-TED unit 14 and the IP/MPLS-TED unit 13. As shown in FIG.6, the IP/MPLS node has the IP/MPLS-TED unit 13. As shown in FIG. 5, theGMPLS node as a core node (hereunder, GMPLS node (core)) has theGMPLS-TED unit 14. In the IP/MPLS node, the PSC-LSP in the GMPLS cloudis treated as a normal link between the IP/MPLSs. The link state whichis advertised by the GMPLS routing protocol is not advertised to theIP/MPLS node.

FIG. 4 shows the structure of a control unit of the GMPLS+IP/MPLS node(edge). The control unit of the GMPLS+IP/MPLS node (edge) comprises; anMPLS signaling unit 17, a GMPLS signaling unit 10, an IP/MPLS routingunit 18, a GMPLS routing unit 11, an IP/MPLS-TED unit 13, and aGMPLS-TED unit 14. They are controlled by a control unit controller 20.The GMPLS signaling unit 10 is operated for example by a GMPLS-RSVP-TEprotocol (for example, refer to Non Patent Document 5). The MPLSsignaling unit 17 is operated for example by an RSVP-TE protocol (forexample, refer to Non Patent Document 6).

FIG. 5 shows the structure of a control unit of the GMPLS node (core) n.The control unit of the GMPLS node (core) comprises a GMPLS signalingunit 10, a GMPLS routing unit 11, and a GMPLS-TED unit 14. They arecontrolled by a control unit controller 20. The GMPLS node (core) is notnecessarily matched with the IP/MPLS protocol.

FIG. 6 shows the structure of a control unit of the IP/MPLS node. Thecontrol unit of the IP/MPLS node comprises an MPLS signaling unit 17, anIP/MPLS routing unit 18, and an IP/MPLS-TED unit 13. They are controlledby a control unit controller 20. The IP/MPLS node is not necessarilymatched with the GMPLS protocol.

The IP/MPLS node can be operated without considering the GMPLS protocol.In the IP/MPLS node, traffic engineering can be performed withoutconsidering the GMPLS protocol. On the other hand, in the GMPLS cloud,traffic engineering can be performed by the GMPLS protocol.

EXAMPLE 2

In the case of realizing a link interface, there is a numbered systemexpressed by allocating the IP address, and an unnumbered systemexpressed by the combination of the IP address being the node identifierand the link identifier which is uniquely allocated in the node. A linkexpressed using the numbered system is called a numbered link, and alink expressed using the unnumbered system is called an unnumbered link(for example, refer to Non Patent Document 7).

Hereunder is a description of the unnumbered link. The IP address isnormally allocated to the link interface in the MPLS network. The linkin the network can be identified by the IP address. However, the GMPLShas a capacity of 100 or more wavelengths per fiber. If the IP addressesare allocated to the respective wavelength interfaces, the number ofrequired IP addresses becomes enormous. Moreover, the LSPs of therespective layers are advertised as a TE link with respect to the upperlayer so that, if the IP addresses are allocated with respect to therespective TE links, there is concern of a shortage of resources for theIP address.

In view of the above, in the GMPLS, in order to identify the link(hereunder, TE link is simply called link in some cases), the linkidentifier which is allocated to the link interface is introduced.Although it is required to globally allocate the IP address, it isapplicable as long as the link identifier is unique in the respectiverouters. The link in the network can be identified by the combination of(node identifier, link identifier).

A link expressed by the combination of (node identifier, linkidentifier) is called an unnumbered link. Unnumbered means that the IPaddress is not allocated to the link interface. Therefore, in GMPLS,even if the number of wavelengths is increased or the number of TE linksis increased, the problem of shortages of IP addresses is solved.

Due to such reasons, the unnumbered system is normally used in the GMPLScloud. However, in the case where the IP/MPLS node treats only thenumbered link and can not treat the unnumbered link, if the PSC-LSP isestablished between the GMPLS+IP/MPLS nodes (edge), it is necessary tomake the PSC-LSP the unnumbered link.

An example of a numbered link and an unnumbered link is shown in FIG. 7Aand FIG. 7B. As shown in FIG. 7A, for the GMPLS+IP/MPLS node or theGMPLS node in the GMPLS cloud, the links of the respective layers arethe unnumbered links except for the PSC-LSP. The PSC-LSP is establishedas the numbered link. As shown in FIG. 7B, for the IP/MPLS node outsideof the GMPLS cloud, in the case of the PSC-LSP, the numbered link usedwithin the GMPLS cloud is used.

An example of a numbered link and an unnumbered link is shown in FIG. 8Aand FIG. 8B. As shown in FIG. 8A, for the GMPLS+IP/MPLS node or theGMPLS node in the GMPLS cloud, the links of all the layers in the GMPLScloud are the unnumbered links. As shown in FIG. 8B, for the IP/MPLSnode outside of the GMPLS cloud, in the case of the PSC-LSP, thenumbered link used within the GMPLS cloud is converted into theunnumbered link and used.

In this way, even in the case where the IP/MPLS node treats only thenumbered link, the IP/MPLS node can be operated without considering theGMPLS protocol, by establishing the PSC-LSP as the numbered link.

EXAMPLE 3

In the case where the PSC-LSP is treated as the numbered link, the IPaddress is required to be allocated to the interface of this link in theGMPLS+IP/MPLS node (edge). The value of the IP address must be allocateduniquely inside the network. The IP address allocated to the PSC-LSPinterface of the respective nodes should not be overlapped.

As shown in FIG. 9, assuming that the PSC-LSP is dynamicallyestablished, the respective GMPLS+IP/MPLS nodes (edge) previously storethe IP address which can be allocated by its own node, in the IP addresspool 16. The IP address stored in the IP address pool 16 is the uniquevalue in the network. If the PSC-LSP is established, the respectivenodes select one IP address to be allocated to the link from the IPaddress pool 16, and obtain it as the IP address of the link of thisinterface. The operation is performed on the opposite ends of theGMPLS+IP/MPLS node (edge). The IP address obtained by its own node isnotified by a message to the opposite GMPLS+IP/MPLS node (edge).

FIG. 10 shows the structure of a GMPLS+IP/MPLS node (edge) which has anIP address pool 16. The structure in FIG. 10 corresponds to theestablishment example in FIG. 7A and FIG. 7B. That is, in theestablishment example in FIG. 7A and FIG. 7B, as shown in FIG. 7A, thePSC-LSP is identified by the numbered system, even in the GMPLS cloud.FIG. 11 shows the structure of a GMPLS+IP/MPLS node (edge) which has anIP address pool 16 and a numbered/unnumbered converting unit 15. Thestructure in FIG. 11 corresponds to the establishment example in FIG. 8Aand FIG. 8B. That is, in the establishment example in FIG. 8A and FIG.8B, as shown in FIG. 8A, the numbered/unnumbered converting unit 15 canbe used so as to completely apply an unnumbered system, in the GMPLScloud.

In this manner, even if the PSC-LSP is dynamically established, bypreviously storing the IP address in the IP address pool 16, the IPaddress of the link can also be dynamically allocated.

EXAMPLE 4

In example 1 to example 3 described above, the GMPLS+IP/MPLS node in theGMPLS network which can process the IP/MPLS protocol is limited to theedge node which is directly connected to the IP network. In example 4,as shown in FIG. 12, GMPLS+IP/MPLS nodes are positioned in the GMPLSnetwork so that even the core node which is not directly connected tothe IP network can process the GMPLS protocol and the IP/MPLS protocol.

The establishment condition of the LSP establishment in example 4 isdescribed with reference to FIG. 13A to FIG. 13C. The PSC-LSP isestablished between a GMPLS+IP/MPLS node (edge) 32 and a GMPLS+IP/MPLSnode (core) 36. Moreover, the PSC-LSP is established between theGMPLS+IP/MPLS node (core) 36 and a GMPLS+IP/MPLS node (edge) 39. Sincethe PSC-LSP is established through the LSC-LSP, the LSC-LSP isestablished before the PSC-LSP is established. Therefore, theGMPLS+IP/MPLS node (edge) is used as a normal link of the IP/MPLS, forthe IP/MPLS node outside of the GMPLS network.

If an MPLS-LSP is established to an IP/MPLS node 31 and an IP/MPLS node41, the MPLS-LSP uses the PSC-LSP as a normal link for the IP/MPLS node.Therefore, the IP packet passes through the MPLS-LSP.

Moreover, in some cases the IP/MPLS node 31 transfers the IP packet tothe IP/MPLS node 41, not through the MPLS-LSP. In this case, thePSC-LSPs established between the GMPLS+IP/MPLS node (edge) 32 and theGMPLS+IP/MPLS node (core) 36, and between the GMPLS+IP/MPLS node (core)36 and the GMPLS+IP/MPLS node (edge) 39 are used as a normal link forthe IP/MPLS node.

FIG. 14 shows the management condition of the link state information inthe network comprising the IP/MPLS node, the GMPLS+IP/MPLS node, and theGMPLS node. In FIG. 14, topology information held by the IP/MPLS node isshown. The difference of example 4 from example 1 is that theGMPLS+IP/MPLS node (core) 36 can behave as the IP/MPLS router for theIP/MPLS network, even if the GMPLS+IP/MPLS node (core) 36 is notdirectly connected to the IP/MPLS network.

The GMPLS node in the GMPLS cloud manages the link state of the GMPLS.For example, if the link state is advertised in the GMPLS using therouting protocol for GMPLS, Opaque LSA is used (for example, refer toNon Patent Documents 2, 4, and 8). The PSC-LSP established between theGMPLS+IP/MPLS nodes is advertised in the same form as the link betweenthe IP/MPLS nodes, so that it can be treated as a normal link for theIP/MPLS router. For example, if OSPF routing protocol is used, therouter LSA is used (for example, refer to Non Patent Document 2).

The GMPLS+IP/MPLS node (edge) has the GMPLS-TED and the IP/MPLS-TED. TheIP/MPLS node has the IP/MPLS-TED. The GMPLS+IP/MPLS node (core) has theGMPLS-TED. In the IP/MPLS node, the PSC-LSP in the GMPLS cloud istreated as a normal link between the IP/MPLSs. The link state which isadvertised by the GMPLS routing protocol is not advertised to theIP/MPLS node.

In example 4, compared to example 1, it can behave as the IP/MPLS routereven if it is not the GMPLS+IP/MPLS node (edge). Therefore trafficengineering can be flexibly performed.

EXAMPLE 5

In example 1 and example 4, if the OSPF routing protocol is used so asto advertise the PSC-LSP to the IP/MPLS network, the router LSA is used.As another scheme, an Opaque LSA within a range of the MPLS parametersnot using a GMPLS extension may be used (for example, refer to NonPatent Document 8). In this case, the link state information of theGMPLS label path is advertised to the IP/MPLS node by the Opaque LSAwhich can be processed by the MPLS router, as a normal link in theIP/MPLS node. Therefore, the MPLS traffic engineering can be performedin the IP/MPLS network.

EXAMPLE 6

The respective examples shown below are modified versions of theabovementioned examples 1 to 5. Firstly, the modified points in examples1 to 5 are described.

Generally, the GMPLS network comprises two types of networks. The firstis a network for transferring the control packet of the protocol whichcontrols the network, represented by the routing protocol or thesignaling protocol. This network is called a Control Plane (C-plane).The second is a network where the label path is established by thecontrol protocol. This network is called a Data Plane (D-plane) and theuser's data packet is transferred through the label path of thisD-plane.

In the GMPLS network, the network topology is advertised by the routingprotocol. For example, in the case of an OSPF routing protocol, thenetwork topology of the C-plane is advertised by the router LSA, and thenetwork topology comprising the label path of the D-plane is advertisedby the Opaque LSA.

As shown in the abovementioned examples, when the label path isadvertised to the IP/MPLS network, it is advertised by the router LSA(since it is a special router LSA for advertising the label path to theIP/MPLS network, it is called a “label path router LSA” hereunder).However, in the abovementioned examples, this label path router LSA isalso advertised to the inside of the GMPLS network. Generally, the GMPLSnode manages the C-plane and the D-plane separately. However if thelabel path router LSA is advertised, the GMPLS network can notdistinguish whether the advertised router LSA is the original router LSAthat expresses the C-plane or the label path router LSA. That is, anetwork having the C-plane and the label path mixed is recognized.

Hereunder is a description of a method for solving such problems in therouting protocol in the respective examples.

The GMPLS+IP/MPLS node in the respective examples described below is aversion having components added to the GMPLS+IP/MPLS node in therespective examples described above. Therefore, in the respectiveexamples below, only the components of these characteristic parts areillustrated, and the components of the GMPLS+IP/MPLS node which arealready shown in the respective examples described above (refer to FIG.4, FIG. 10, FIG. 11 and the like) are not illustrated.

As described before, the GMPLS+IP/MPLS node advertises the link stateinformation of the GMPLS label path of the packet layer to the IP/MPLSnode by the router LSA as the normal link in the IP/MPLS node.Therefore, the GMPLS+IP/MPLS node has the function of converting theOpaque LSA for advertising the label path in the GMPLS network, into therouter LSA to advertise it to the IP/MPLS network. Moreover, at the sametime advertising the router LSA, the GMPLS+IP/MPLS node also has thefunction of generating the Opaque LSA having a given flag for explicitlyshowing that the GMPLS+IP/MPLS node itself advertises the label path tothe IP/MPLS network, to advertise it. This flag also shows that theOpaque LSA for advertising the label path in the GMPLS network isconverted into the router LSA. Therefore it is called a “label pathconversion flag” hereunder.

FIG. 15 is a block diagram showing the structure of an LSA convertingunit 50 provided in the GMPLS+IP/MPLS node, according to the presentexample. This LSA converting unit 50 realizes the two functionsdescribed above. It comprises an Opaque LSA converting unit 51, a routerLSA generating unit 52, and an LSA advertising unit 53.

The Opaque LSA converting unit 51 outputs the Opaque LSA for advertisingto the IP/MPLS network, to the router LSA generating unit 52, and addsthe label path conversion flag to the Opaque LSA, then outputs it to theLSA advertising unit 53. The router LSA generating unit 52 converts theOpaque LSA output from the Opaque LSA converting unit 51 into the routerLSA, and outputs it to the LSA advertising unit 53. The LSA advertisingunit 53 advertises the Opaque LSA having the added label path conversionflag which is output from the Opaque LSA converting unit 51 and therouter LSA which is output from the router LSA generating unit 52, tothe other nodes.

FIG. 16 shows the correspondence of the Opaque LSA parameters used inGMPLS, and the router LSA parameters used in MPLS. Examples ofparameters relevant to the present application among the parameters notshown in the drawings include Advertising Router and LS Sequence numberwhich are common to the Opaque LSA and the router LSA.

Next is a description of the operation performed by the LSA convertingunit 50 for converting the Opaque LSA expressing the label path of theD-plane in the GMPLS network, into the router LSA.

Case (1): The Label Path is the Numbered System, and the Link Type isPoint-to-Point.

The LSA converting unit 50 changes the Link-State Advertisement Type to1, copies an Advertising Router value and an LS Sequence number value,copies the Link ID field value in the Opaque LSA to the Link ID field ofthe router LSA, and copies the Local interface IP address field value inthe Opaque LSA to the Link Data field of the router LSA expressing therouter interface's IP address. A “1” for the value of the Link-StateAdvertisement Type means the router LSA.

Case (2): The Label Path is the Unnumbered System, and the Link Type isPoint-to-Point.

The LSA converting unit 50 changes the Link-State Advertisement Type to1, copies an Advertising Router value and an LS Sequence number value,copies the Link ID field value in the Opaque LSA to the Link ID field ofthe router LSA, and copies the Link Local Identifiers field value in theOpaque LSA to the Link Data field of the router LSA expressing theifIndex value.

Case (3): The Link Type of the Label Path is Multi-Access.

The LSA converting unit 50 changes the Link-State Advertisement Type to1, copies an Advertising Router value and an LS Sequence number value,copies the Link ID field value in the Opaque LSA to the Link ID field ofthe router LSA, and copies the Local interface IP address field value inthe Opaque LSA to the Link Data field of the router LSA expressing therouter interface's IP address.

By installing the above functions, it becomes possible to generate arouter LSA which plays a role of advertising the GMPLS label path to theMPLS network. As shown in FIG. 16, the router LSA thus generatedreflects values in the original Opaque LSA, and copies the AdvertisingRouter and the LS sequence number to succeed them.

EXAMPLE 7

FIG. 17 is a block diagram showing a structure of a router LSAidentifying unit 60 provided in the GMPLS+IP/MPLS node according to thepresent example. This router LSA identifying unit 60 comprises an LSAjudging unit 61 and the abovementioned GMPLS-TED unit 14.

The LSA judging unit 61 inquires to the GMPLS-TED unit 14 of its ownnode, so that it can identify whether the router LSA advertises theC-plane of the GMPLS, or whether it is converted from the GMPLS labelpath, in the case where the router LSA generated by another node hasbeen received.

That is, the LSA judging unit 61 searches in the GMPLS-TED unit 14 usingas a key, the Advertising Router value and the LS Sequence number valueincluded in the router LSA received from another node. If an Opaque LSAin which the Advertising Router value and the LS Sequence number valueare the same as those in the received router LSA is stored in theGMPLS-TED unit 14, it judges that the received router LSA is generatedby converting the Opaque LSA expressing the GMPLS label path (that is,the label path router LSA).

By installing the above functions, it becomes possible to identifywhether the router LSA advertised to the network expresses the C-planeof the GMPLS network or whether it is generated by converting the OpaqueLSA expressing the D-plane label path. Therefore, the GMPLS node candetermine which router LSA should be used for generating the C-planetopology and which router LSA should be used for generating the D-planetopology.

EXAMPLE 8

The present example is another example of generating a router LSA whichplays a role of advertising the GMPLS label path to the MPLS network.The structure of the GMPLS+IP/MPLS node according to the present exampleis similar to that of example 6, but the operation of the LSA convertingunit 50 is partially different from that of example 6.

Hereunder is a description of the operation of the LSA converting unit50 which converts the Opaque LSA into the router LSA.

Case (1): The Label Path is the Numbered system, and the Link Type isPoint-to-Point.

The LSA converting unit 50 changes the Link-State Advertisement Type to1, copies an Advertising Router value, turns the label path conversionflag on, copies the Link ID field value in the Opaque LSA to the Link IDfield of the router LSA, and copies the Local interface IP address fieldvalue in the Opaque LSA to the Link Data field of the router LSAexpressing the router interface's IP address.

Case (2): The Label Path is the Unnumbered System, and the Link Type isPoint-to-Point.

The LSA converting unit 50 changes the Link-State Advertisement Type to1, copies an Advertising Router value, turns the label path conversionflag on, copies the Link ID field value in the Opaque LSA to the Link IDfield of the router LSA, and copies the Link Local Identifiers fieldvalue in the Opaque LSA to the Link Data field of the router LSAexpressing the ifIndex value.

Case (3): The Link Type of the Label Path is Multi-Access.

The LSA converting unit 50 changes the Link-State Advertisement Type to1, copies an Advertising Router value, turns the label path conversionflag on, copies the Link ID field value in the Opaque LSA to the Link IDfield of the router LSA, and copies the Local interface IP address fieldvalue in the Opaque LSA to the Link Data field of the router LSAexpressing the router interface's IP address.

By installing the above functions, it becomes possible to generate arouter LSA which plays a role of advertising the GMPLS label path to theMPLS network. As shown in FIG. 16, the router LSA thus generatedreflects values in the original Opaque LSA, copies an Advertising Routervalue to succeed it, and turns the label path conversion flag on.

EXAMPLE 9

The present example is another example of identifying whether the routerLSA generated by another node advertises the GMPLS C-plane or whether itis converted from the GMPLS label path. The structure of theGMPLS+IP/MPLS node according to the present example is similar to thatof example 7, but the operation of the LSA judging unit 61 is differentfrom that of example 7.

That is, the LSA judging unit 61 according to the present examplesearches in the GMPLS-TED unit 14 of its own node using as a key, theAdvertising Router value and the label path conversion flag included inthe router LSA received from another node. If an Opaque LSA with thesame Advertising Router value and with the label conversion flag turnedon is stored in the GMPLS-TED unit 14, it judges that the receivedrouter LSA is a label path router LSA generated by converting the OpaqueLSA expressing the GMPLS label path.

By implementing the above functions, it becomes possible to identifywhether the router LSA advertised to the network expresses the C-planeof the GMPLS network or whether it is generated by converting the OpaqueLSA expressing the D-plane label path. Therefore, the GMPLS node candetermine which router LSA should be used for generating the C-planetopology and which router LSA should be used for generating the D-planetopology.

EXAMPLE 10

FIG. 18 is a block diagram showing a structure of the network forexplaining the present example. The diagram shows an example wherein thenetwork comprises IP/MPLS nodes 71 and 72, GMPLS+IP/MPLS nodes (edge) 73and 74, and a GMPLS+IP/MPLS node (core) 75. Moreover, FIG. 19 shows apath establishment sequence of the network of the present example.

In the case where the C-plane topology of the GMPLS network isadvertised by the router LSA, the IP/MPLS node receiving this recognizesthe C-plane topology of the GMPLS network, and the IP/MPLS node havingthis topology information outputs the request to specify the C-plane ofthe GMPLS network and to establish the MPLS label path, then in the casewhere there is a GMPLS label path having the corresponding nodes onopposite ends of the C-plane link on the route specified by thisrequest, the route specified for this GMPLS label path is allocated.

By installing the above functions, when establishing the MPLS path fromthe IP/MPLS node outside of the GMPLS network via the GMPLS network, itbecomes possible to specify a route inside of the GMPLS network, toestablish the path.

Assuming the case where the route specified by the IP/MPLS node 71 isthe C-plane link of the GMPLS network, the GMPLS+IP/MPLS node (edge) 73in the GMPLS network, and the GMPLS+IP/MPLS node (core) 75 on the route,read the C-plane specification to convert into the D-plane link (labelpath) corresponding to this C-plane, to establish the route.

The C-plane is originally a network for transferring control signals.Therefore this is not necessarily limited to maintaining a band fortransferring large volumes of data. Thus, by providing theabovementioned functions, even if the C-plane of the GMPLS networkvisible from the IP/MPLS node is specified as a route, the presentexample can allocate an appropriate network for transferring data byautomatically switching to the corresponding D-plane on the same route.

The route specified by the IP/MPLS nodes is the C-plane shown by brokenlines in the example of FIG. 18. In this case, if the existing GMPLSlabel path shown by thick lines is established (if the label path foradvertising to the IP/MPLS network is already established), the relayingGMPLS+IP/MPLS node (edge) 73 and the GMPLS+IP/MPLS node (core) 75 readit and convert the route into the D-plane label path.

The sequence at this time is shown in FIG. 19. As shown in FIG. 19, ifthe IP/MPLS node 71 performs the MPLS label path establishment request(PATH message), the GMPLS+IP/MPLS node (edge) 73 reads the C-planespecification to convert into the D-plane specification to establish theroute, and the GMPLS+IP/MPLS node (core) 75 performs in a similar way.Then, when the MPLS label path establishment request is seriallytransferred to the IP/MPLS node 72, the MPLS label path establishmentrequest response (RESV message) is generated by the IP/MPLS node 72 inresponse to this request, and serially transferred to the IP/MPLS node71.

EXAMPLE 11

FIG. 20 shows a path establishment sequence in the present example. Thenetwork structure of the present example is the same as that of FIG. 18referred to in example 10.

Similarly to example 10, in the case where the C-plane topology of theGMPLS network is advertised by the router LSA, the IP/MPLS nodereceiving this recognizes the C-plane topology of the GMPLS network, andthe IP/MPLS node having this topology information outputs the request tospecify the C-plane of the GMPLS network and to establish the MPLS labelpath, then the present example is for the case where there is no GMPLSlabel path having the corresponding nodes on opposite ends of theC-plane link on the route specified by this request. In this case, theGMPLS+IP/MPLS node of the present example uses the MPLS label pathestablishment request output from the aforementioned IP/MPLS node as thetrigger, so as to newly establish the label path to the D-planecorresponding to the opposite nodes of the C-plane link, and allocatesthe route specified with respect to the newly established label path.

By installing the above functions, then even in a case where the MPLSnode specifies the C-plane of the GMPLS network as the route, and in acase where there is no corresponding label path on the correspondinglink, it becomes possible to automatically and newly generate thecorresponding label path and establish the MPLS path using the new labelpath.

FIG. 20 shows the establishment sequence for the MPLS label path at thistime. As shown in FIG. 20, the IP/MPLS node 71 outputs the MPLS labelpath establishment request (PATH message). The GMPLS+IP/MPLS node (edge)73 receives this MPLS label path establishment request. If theGMPLS+IP/MPLS node (edge) 73 detects that there is no GMPLS label pathhaving the corresponding nodes on opposite ends of the C-plane link onthe route specified by the MPLS label path establishment request, theGMPLS+IP/MPLS node (edge) 73 generates the GMPLS label pathestablishment request (PATH message). This GMPLS label pathestablishment request is transferred to the GMPLS+IP/MPLS node (edge) 74via the GMPLS+IP/MPLS node (core) 75. Accordingly, the label path isnewly established in the D-plane. In response to this GMPLS label pathestablishment request, the GMPLS+IP/MPLS node (edge) 74 generates theGMPLS label path establishment request response and this GMPLS labelpath establishment request response is transferred to the GMPLS+IP/MPLSnode (edge) 73. At this time, the respective GMPLS+IP/MPLS nodesallocate the route specified for the newly established label path. Then,similarly to example 10, the MPLS label path establishment request istransferred to the IP/MPLS node 72, and then the MPLS label pathestablishment request response is transferred to the IP/MPLS node 71.

EXAMPLE 12

In the present example, in the case where the GMPLS label path havingthe corresponding nodes on opposite ends of the C-plane link of theGMPLS network specified by the IP/MPLS node is allocated as in theabovementioned example 10 or example 11, the GMPLS+IP/MPLS node whichdirectly receives the request from the IP/MPLS node transfers the datawhich is transferred from the IP/MPLS node, not to the route specifiedby the IP/MPLS node, but to the GMPLS label path allocated as describedabove. That is, in the case where the GMPLS+IP/MPLS node (edge) convertsthe label path route specifying the C-plane into the D-plane label path,then synchronized with this, the routing table (not shown) of thisGMPLS+IP/MPLS node (edge) is rewritten, and transfer to the D-planelabel path is performed.

As above, preferred examples of the present invention are described withreference to the drawings. However the present invention is not limitedto the example described above and for example, the components of theseexamples may be suitably combined.

INDUSTRIAL APPLICABILITY

According the present invention, it becomes possible to realize anetwork having MPLS and IP/MPLS mixed, in which the IP/MPLS node can beoperated as is without replacing the IP/MPLS node with a node having aGMPLS function, even if the GMPLS and IP/MPLS are mixed. Accordingly,the applicable range of the node is widened, enabling a decrease in thecost of the node. Moreover, since the number of types of arranged nodescan be decreased, when designing the network, the degree of freedom ofdesign can be improved. Furthermore, according to the present invention,in the case where the GMPLS network and the IP/MPLS network areconnected, the routing protocol can be normally operated. Therefore, byperforming traffic engineering based on this, it becomes possible todistribute the traffic, and to effectively use the network resources.

1. A GMPLS+IP/MPLS node which is used in a network in which a GMPLS(Generalized Multi Protocol Label Switching) network and an IP (InternetProtocol) network are mixed, the GMPLS network comprising a node havinga GMPLS function, the IP network comprising an IP/MPLS (InternetProtocol/Multi Protocol Label Switching) node, and which constitutes theGMPLS network, and which processes a GMPLS protocol and an IP/MPLSprotocol, the GMPLS+IP/MPLS node comprising: a device which establishesa GMPLS label path of a packet layer with another GMPLS+IP/MPLS node inthe GMPLS network; and a device which tunnel transfers a packettransferred from the IP/MPLS node with the other GMPLS+IP/MPLS nodethrough the GMPLS label path.
 2. A GMPLS+IP/MPLS node according to claim1, further comprising a device which advertises link state informationof the GMPLS label path of the packet layer to the IP/MPLS node by arouter LSA (Label Switching Advertisement) as a normal link in theIP/MPLS node.
 3. A GMPLS+IP/MPLS node according to claim 2, furthercomprising: a device which holds the link state information having theGMPLS label path of the packet layer advertised as the link; and adevice which holds link state information inside of the GMPLS network.4. A GMPLS+IP/MPLS node according to claim 2, further comprising adevice which converts a link of PSC-LSP (Packet Switch Capable-LabelSwitch Path) used for IP/MPLS from an unnumbered system into a numberedsystem to advertise as the link of the numbered system.
 5. AGMPLS+IP/MPLS node according to claim 2, further comprising: a devicewhich performs processing inside of the GMPLS network in accordance withan unnumbered system; and a device which converts a link of PSC-LSP usedfor IP/MPLS from the unnumbered system into a numbered system toadvertise as the link of the numbered system.
 6. A GMPLS+IP/MPLS nodeaccording to claim 2, further comprising a device which advertises theGMPLS label switch path of the packet layer as a link of a numberedsystem.
 7. A GMPLS+IP/MPLS node according to claim 2, furthercomprising: a device which performs processing inside of the GMPLSnetwork in accordance with an unnumbered system; and a device whichconverts the GMPLS label switch path of the packet layer from theunnumbered system into a numbered system to advertise as the link of thenumbered system.
 8. A GMPLS+IP/MPLS node according to any one of claim 4through claim 7, further comprising: a device which previously stores anIP address; and a device which uses the stored IP address as an IPaddress of the link of the numbered system.
 9. A GMPLS+IP/MPLS nodeaccording to claim 2, further comprising an LSA converting device whichconverts an Opaque LSA expressing a D-plane label path in the GMPLSnetwork into a router LSA, wherein when the label path is apoint-to-point Link type of a numbered system, the LSA converting devicechanges a Link-State Advertisement Type to 1 corresponding to the routerLSA, copies an Advertising Router value and an LS Sequence number value,copies a Link ID field value in the Opaque LSA to a Link ID field of therouter LSA, and copies a Local interface IP address field value in theOpaque LSA to a Link Data field of the router LSA expressing a routerinterface's IP address.
 10. A GMPLS+IP/MPLS node according to claim 2,further comprising an LSA converting device which converts an Opaque LSAexpressing a D-plane label path in the GMPLS network into a router LSA,wherein when the label path is a point-to-point Link type of anunnumbered system, the LSA converting device changes a Link-StateAdvertisement Type to 1 corresponding to the router LSA, copies anAdvertising Router value and an LS Sequence number value, copies a LinkID field value in the Opaque LSA to a Link ID field of the router LSA,and copies a Link Local Identifiers field value in the Opaque LSA to aLink Data field of the router LSA expressing an ifIndex value.
 11. AGMPLS+IP/MPLS node according to claim 2, further comprising an LSAconverting device which converts an Opaque LSA expressing a D-planelabel path in the GMPLS network into a router LSA, wherein when thelabel path is a multi-access Link type, the LSA converting devicechanges a Link-State Advertisement Type to 1 corresponding to the routerLSA, copies an Advertising Router value and an LS Sequence number value,copies a Link ID field value in the Opaque LSA to a Link ID field of therouter LSA, and copies a Local interface IP address field value in theOpaque LSA to a Link Data field of the router LSA expressing a routerinterface's IP address.
 12. A GMPLS+IP/MPLS node according to any one ofclaim 9 through claim 11, further comprising: an LSA identifying devicewhich receives a router LSA generated by another GMPLS+IP/MPLS node andidentifies whether the router LSA advertises a C-plane of the GMPLSnetwork, or whether the router LSA is obtained by converting an OpaqueLSA expressing the GMPLS label path; and a link state holding devicewhich holds link state information of the GMPLS network, wherein the LSAidentifying device searches the link state holding device of theGMPLS+IP/MPLS node itself using an Advertising Router value and an LSSequence number value included in the received router LSA as a key, andwhen link state information having the same Advertising Router and LSSequence number as the received router LSA is held in the link stateholding device, the LSA identifying device judges that the receivedrouter LSA is obtained by converting the Opaque LSA expressing the GMPLSlabel path.
 13. A GMPLS+IP/MPLS node according to claim 2, furthercomprising an LSA converting device which converts an Opaque LSAexpressing a D-plane label path in the GMPLS network into a router LSA,wherein when the label path is a point-to-point Link type of a numberedsystem, the LSA converting device changes a Link-State AdvertisementType to 1 corresponding to the router LSA, copies an Advertising Routervalue, turns on a label path conversion flag which shows that the OpaqueLSA expressing the D-plane label path in the GMPLS network is convertedinto the router LSA, copies a Link ID field value in the Opaque LSA to aLink ID field of the router LSA, and copies a Local interface IP addressfield value in the Opaque LSA to a Link Data field of the router LSAexpressing a router interface's IP address.
 14. A GMPLS+IP/MPLS nodeaccording to claim 2, further comprising an LSA converting device whichconverts an Opaque LSA expressing a D-plane label path in the GMPLSnetwork into a router LSA, wherein when the label path is apoint-to-point Link type of an unnumbered system, the LSA convertingdevice changes a Link-State Advertisement Type to 1 corresponding to therouter LSA, copies an Advertising Router value, turns on a label pathconversion flag which shows that the Opaque LSA expressing the D-planelabel path in the GMPLS network is converted into the router LSA, copiesa Link ID field value in the Opaque LSA to a Link ID field of the routerLSA, and copies a Link Local Identifiers field value in the Opaque LSAto a Link Data field of the router LSA expressing an ifIndex value. 15.A GMPLS+IP/MPLS node according to claim 2, further comprising an LSAconverting device which converts an Opaque LSA expressing a D-planelabel path in the GMPLS network into a router LSA, wherein when thelabel path is a multi-access Link type, the LSA converting devicechanges a Link-State Advertisement Type to 1 corresponding to the routerLSA, copies an Advertising Router value, turns on a label pathconversion flag which shows that the Opaque LSA expressing the D-planelabel path in the GMPLS network is converted into the router LSA, copiesa Link ID field value in the Opaque LSA to a Link ID field of the routerLSA, and copies a Local interface IP address field value in the OpaqueLSA to a Link Data field of the router LSA expressing a routerinterface's IP address.
 16. A GMPLS+IP/MPLS node according to any one ofclaim 13 through claim 15, further comprising: an LSA identifying devicewhich receives a router LSA generated by another GMPLS+IP/MPLS node andidentifies whether the router LSA advertises a C-plane of the GMPLSnetwork, or whether the router LSA is obtained by converting an OpaqueLSA expressing the GMPLS label path; and a link state holding devicewhich holds link state information of the GMPLS network, wherein the LSAidentifying device searches the link state holding device of theGMPLS+IP/MPLS node itself using an Advertising Router value and a labelpath conversion flag included in the received router LSA as a key, andwhen link state information having the same Advertising Router value asthe received router LSA and having the label path conversion flag turnedon is held in the link state holding device, the LSA identifying devicejudges that the received router LSA is obtained by converting the OpaqueLSA expressing the GMPLS label path.
 17. A GMPLS+IP/MPLS node accordingto claim 2, further comprising a device which, when a C-plane topologyof the GMPLS network is advertised by the router LSA, an IP/MPLS nodereceiving the router LSA recognizes the C-plane topology of the GMPLSnetwork, and an IP/MPLS node having information regarding the topologyoutputs a request to specify the C-plane of the GMPLS network and toestablish an MPLS label path, and if there is a GMPLS label path havingthe corresponding nodes on opposite ends of a C-plane link on a routespecified by the request, allocates the specified route to the GMPLSlabel path.
 18. A GMPLS+IP/MPLS node according to claim 2, furthercomprising a device which, when a C-plane topology of the GMPLS networkis advertised by the router LSA, an IP/MPLS node receiving the routerLSA recognizes the C-plane topology of the GMPLS network, and an IP/MPLSnode having information regarding the topology outputs a request tospecify the C-plane of the GMPLS network and to establish an MPLS labelpath, and if there is no GMPLS label path having the corresponding nodeson opposite ends of a C-plane link on a route specified by the request,in response to an MPLS label path establishment request output from theIP/MPLS node, newly establishes a label path on a D-plane correspondingto opposite nodes of the C-plane link, and allocates the specified routeto the newly established label path.
 19. A GMPLS+IP/MPLS node accordingto claim 17 or claim 18, further comprising a device which, when theGMPLS label path having the corresponding nodes on opposite ends of theC-plane link of the GMPLS network specified by the IP/MPLS node isallocated, and if the GMPLS+IP/MPLS node itself directly receives therequest from the IP/MPLS node, transfers data which is transferred fromthe IP/MPLS node, not to the route specified by the IP/MPLS node, but tothe allocated GMPLS label path.
 20. An IP/MPLS node which is used in anetwork in which a GMPLS network and an IP network are mixed, the GMPLSnetwork comprising a node having a GMPLS function, the IP networkcomprising an IP/MPLS node, and which is connected to the GMPLS network,and a GMPLS+IP/MPLS node which constitutes the GMPLS network and whichis capable of processing a GMPLS protocol and an IP/MPLS protocolestablishes a GMPLS label path of a packet layer with anotherGMPLS+IP/MPLS nodes in the GMPLS network, the IP/MPLS node comprising adevice which holds link state information having a GMPLS label path ofthe packet layer advertised as a link.
 21. A network in which GMPLS andIP/MPLS are mixed, comprising: a GMPLS+IP/MPLS node according to any oneof claim 1 through claim 19, and an IP/MPLS node which is connected tothe GMPLS network, and which is provided with a device which holds linkstate information having a GMPLS label path of the packet layeradvertised as a link.
 22. A packet communication method in a network inwhich a GMPLS network and an IP network are mixed, the GMPLS networkcomprising a node having a GMPLS function, the IP network comprising anIP/MPLS node, and the IP/MPLS node transfers a packet with the nodehaving the GMPLS function, the packet communication method comprising: astep of providing a GMPLS+IP/MPLS node which is capable of processing aGMPLS protocol and an IP/MPLS protocol and which is directly connectedto the IP network among nodes having the GMPLS function constituting theGMPLS network; a step of establishing a GMPLS label path of a packetlayer with another GMPLS+IP/MPLS node in the GMPLS network by theGMPLS+IP/MPLS node; and a step of tunnel transferring a packettransferred from the IP/MPLS node with the other GMPLS+IP/MPLS nodethrough the GMPLS label path.
 23. A packet communication methodaccording to claim 22, wherein link state information of the GMPLS labelpath of the packet layer is advertised to the IP/MPLS node by a routerLSA as a normal link in the IP/MPLS node.
 24. A packet communicationmethod according to claim 22, wherein link state information of theGMPLS label path of the packet layer is advertised to the IP/MPLS nodeby an Opaque LSA which can be processed by an MPLS router as a normallink in the IP/MPLS node.
 25. A packet communication method according toclaim 23, wherein link state information having the GMPLS label path ofthe packet layer advertised as the link is held, and link stateinformation inside of the GMPLS network is held.
 26. A packetcommunication method according to claim 23, wherein a link of PSC-LSPused for IP/MPLS is converted from an unnumbered system into a numberedsystem and is advertised as the link of the numbered system.
 27. Apacket communication method according to claim 23, wherein the GMPLSnetwork performs processing in accordance with an unnumbered system, anda link of PSC-LSP used for IP/MPLS is converted from the unnumberedsystem into a numbered system and is advertised as the link of thenumbered system.
 28. A packet communication method according to claim23, wherein the GMPLS label switch path of the packet layer isadvertised as the link of a numbered system.
 29. A packet communicationmethod according to claim 23, wherein the GMPLS network performsprocessing in accordance with an unnumbered system, and the GMPLS labelswitch path of the packet layer is converted from the unnumbered systeminto a numbered system, and is advertised as the link of the numberedsystem.
 30. A packet communication method according to any one of claim26 through claim 29, wherein an IP address is previously stored, and thestored IP address is used as an IP address of the link of the numberedsystem.
 31. A packet communication method according to claim 23, whereinin order to convert an Opaque LSA expressing a D-plane label path in theGMPLS network into a router LSA, when the label path is a point-to-pointLink type of a numbered system, a Link-State Advertisement Type ischanged to 1 corresponding to the router LSA, an Advertising Routervalue and an LS Sequence number value are copied, a Link ID field valuein the Opaque LSA is copied to a Link ID field of the router LSA, and aLocal interface IP address field value in the Opaque LSA is copied to aLink Data field of the router LSA expressing a router interface's IPaddress.
 32. A packet communication method according to claim 23,wherein in order to convert an Opaque LSA expressing a D-plane labelpath in the GMPLS network into a router LSA, when the label path is apoint-to-point Link type of an unnumbered system, a Link-StateAdvertisement Type is changed to 1 corresponding to the router LSA, anAdvertising Router value and an LS Sequence number value are copied, aLink ID field value in the Opaque LSA is copied to a Link ID field ofthe router LSA, and a Link Local Identifiers field value in the OpaqueLSA is copied to a Link Data field of the router LSA expressing an ifIndex value.
 33. A packet communication method according to claim 23,wherein in order to convert an Opaque LSA expressing a D-plane labelpath in the GMPLS network into a router LSA, when the label path is amulti-access Link type, a Link-State Advertisement Type is changed to 1corresponding to the router LSA, an Advertising Router value and an LSSequence number value are copied, a Link ID field value in the OpaqueLSA is copied to a Link ID field of the router LSA, and a Localinterface IP address field value in the Opaque LSA is copied to a LinkData field of the router LSA expressing a router interface's IP address.34. A packet communication method according to any one of claim 31through claim 33, wherein a router LSA generated by anotherGMPLS+IP/MPLS node is received, and in order to identify whether therouter LSA advertises a C-plane of the GMPLS network or whether therouter LSA is obtained by converting an Opaque LSA expressing the GMPLSlabel path, a link state holding device of its own GMPLS+IP/MPLS nodewhich holds link state information of the GMPLS network is searched,using an Advertising Router value and an LS Sequence number valueincluded in the received router LSA as a key, and when link stateinformation having the same Advertising Router and LS Sequence number asthe received router LSA is held in the link state holding device, it isjudged that the received router LSA is obtained by converting the OpaqueLSA expressing the GMPLS label path.
 35. A packet communication methodaccording to claim 23, wherein in order to convert an Opaque LSAexpressing a D-plane label path in the GMPLS network into a router LSA,when the label path is a point-to-point Link type of a numbered system,a Link-State Advertisement Type is changed to 1 corresponding to therouter LSA, an Advertising Router value is copied, a label pathconversion flag which shows that the Opaque LSA expressing the D-planelabel path in the GMPLS network is converted into the router LSA isturned on, a Link ID field value in the Opaque LSA is copied to a LinkID field of the router LSA, and a Local interface IP address field valuein the Opaque LSA is copied to a Link Data field of the router LSAexpressing a router interface's IP address.
 36. A packet communicationmethod according to claim 23, wherein in order to convert an Opaque LSAexpressing a D-plane label path in the GMPLS network into a router LSA,when the label path is a point-to-point Link type of an unnumberedsystem, a Link-State Advertisement Type is changed to 1 corresponding tothe router LSA, an Advertising Router value is copied, a label pathconversion flag which shows that the Opaque LSA expressing the D-planelabel path in the GMPLS network is converted into the router LSA isturned on, a Link ID field value in the Opaque LSA is copied to a LinkID field of the router LSA, and a Link Local Identifiers field value inthe Opaque LSA is copied to a Link Data field of the router LSAexpressing an ifIndex value.
 37. A packet communication method accordingto claim 23, wherein in order to convert an Opaque LSA expressing aD-plane label path in the GMPLS network into a router LSA, when thelabel path is a multi-access Link type, a Link-State Advertisement Typeis changed to 1 corresponding to the router LSA, an Advertising Routervalue is copied, a label path conversion flag which shows that theOpaque LSA expressing the D-plane label path in the GMPLS network isconverted into the router LSA is turned on, a Link ID field value in theOpaque LSA is copied to a Link ID field of the router LSA, and a Localinterface IP address field value in the Opaque LSA is copied to a LinkData field of the router LSA expressing a router interface's IP address.38. A packet communication method according to any one of claim 35through claim 37, wherein a router LSA generated by anotherGMPLS+IP/MPLS node is received, and in order to identify whether therouter LSA advertises a C-plane of the GMPLS network or whether therouter is obtained by converting an Opaque LSA expressing the GMPLSlabel path, a link state holding device of its own GMPLS+IP/MPLS nodewhich holds link state information of the GMPLS network is searchedusing an Advertising Router value and a label path conversion flagincluded in the received router LSA as a key, and when link stateinformation having the same Advertising Router value as the receivedrouter LSA and having the label path conversion flag turned on is heldin the link state holding device, it is judged that the received routerLSA is obtained by converting the Opaque LSA expressing the GMPLS labelpath.
 39. A packet communication method according to claim 23, whereinthe GMPLS+IP/MPLS node advertises a C-plane topology of the GMPLSnetwork by the router LSA, an IP/MPLS node receiving the router LSArecognizes the C-plane topology of the GMPLS network, an IP/MPLS nodehaving information regarding the topology outputs a request to specifythe C-plane of the GMPLS network and to establish an MPLS label path,and if there is a GMPLS label path having the corresponding nodes onopposite ends of a C-plane link on a route specified by the request, theGMPLS+IP/MPLS node allocates the specified route to the GMPLS labelpath.
 40. A packet communication method according to claim 23, whereinthe GMPLS+IP/MPLS node advertises a C-plane topology of the GMPLSnetwork by the router LSA, an IP/MPLS node receiving the router LSArecognizes the C-plane topology of the GMPLS network, an IP/MPLS nodehaving information regarding the topology outputs a request to specifythe C-plane of the GMPLS network and to establish an MPLS label path,and if there is no GMPLS label path having the corresponding nodes onopposite ends of a C-plane link on a route specified by the request, inresponse to an MPLS label path establishment request output from theIP/MPLS node as a trigger, the GMPLS+IP/MPLS node newly establishes alabel path on a D-plane corresponding to opposed nodes of the C-planelink, and allocates the specified route to the newly established labelpath.
 41. A packet communication method according to claim 39 or claim40, wherein when the GMPLS label path having the corresponding nodes onopposite ends of the C-plane link of the GMPLS network specified by theIP/MPLS node is allocated, a GMPLS+IP/MPLS node which directly receivesthe request from the IP/MPLS node transfers data which is transferredfrom the IP/MPLS node, not to the route specified by the IP/MPLS node,but to the allocated GMPLS label path.
 42. A packet communication methodaccording to claim 23, wherein the IP/MPLS node holds link stateinformation having the GMPLS label path of the packet layer advertisedas a link.
 43. A method for configuring a network in which GMPLS andIP/MPLS are mixed, comprising: providing a GMPLS+IP/MPLS node whichtransfers a packet using a packet communication method according toclaim 22; and providing an IP/MPLS node which transfers a packet, andwhich advertises link state information of the GMPLS label path of thepacket layer to the IP/MPLS node by a router LSA as a normal link in theIP/MPLS node, and which holds link state information having the GMPLSlabel path of the packet layer advertised as the link.